Belt-tightener



(No Model.) 2 SheetsSheet 2. S. W. PUTN AM.

I BELT TIGHTENER.

No. 369,364. Patented Sept. 6, 1887.

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UNITED STATES lnrnr rrien.

SALMON W. PUTNAM, OF FITGHBURG, MASSACHUSETTS.

BELT=TIGHTENER.

SPECIFICATION forming part of Letters Patent No. 369,364, datedSeptember 6, 1887.

Application filed June 16, 1887. Serial No. 241,510. (No model.)

To all whom it may concern.-

Be it known that I, SALMON W. PUTNAM, a citizen of the United States,residing at Fitchburg, in the county of Worcester and State ofMassachusetts, have invented certain new and useful Improvements inBelt-Tighteners, of which the following. is a full, clear, and exactdescription, reference being bad to the accompanying drawings, formingpart of this specification, in which- Figure 1 represents a portion of adrillingmachine having my invention applied thereto. Figs. 2,3, and 4illustrate enlarged detail v-iews of my improvements.

My invention relates to means for tightening machine-belts; and itconsists in the construction and combination of devices,which I shallhereinafter fully describe and claim.

To enable others skilled in the art to which my invention appertains tomake and use the same, I will now describe its construction and indicatethe manner in which the same is carried out.

In the said drawings I have illustrated my invention as applied to ametal-drilling machine, to which it is especially applicable. In ahearing, A, in the upper portion of the column B of the machine issuitably journaled a shaft, U, having end eccentric portions, a, asshown in Fig. 4, on which the idle-pulleys D are suitably mounted. Abelt, E, passes from the cone or driving pulley F over the idlers D tothe pulley G, which in the present case is the pulley to be driven, theperipheries of the pulleys F and G being modified according to thenature of the belt used, as when a flat belt is used the driving-pulleysshould be made with a wider face than is customary; otherwise the beltin being shifted would run over the edge of the pulley when theeccentric was thrown to either extreme, as will be hereinafter setforth.

The ends of the eccentric shaft 0 are bored and internally threaded at bto receive the screw 0, whereby the idlers are held in operativeposition on the shaft, said screws having nuts or squared heads cl,whereby they may be engaged bya wrench or other tool to facilitate theadjustments of the eccentric shaft and the consequent tightening orloosening of the drivingbelt.

From this description it is manifest that by applying a wrench to thenuts (Z the shaft 0 may be turned in its bearing to cause the endeccentrics, a, to increase or lessen the distance between the idlers andthe driven pulley. As the distance between said pulleys is increased bythe eccentric movement of the shaft the belt is tightened, the oppositeeffect being produced by moving the eccentric shaft so as to bring theidlers nearer the driven pulley. Y

By reason of the above construction I am enabled to regulate the tensionof the belt in a positive manner and without the necessity of stoppingthe machine or taking up the belt, as the slightest movement of theeccentrics in or out affects the belt and alters or varies itstension-an important feature, owing to the variation in the amount ofwork thrown on the machine.

Having thus described my inventionnvhatl claim as new, and desire tosecure by Letters Patent, is-

1. A belt-tightener comprising an eccentric shaft having idlepulleysthereon between the driving-pulley and the pulley driven,whereby themovement of said shaft varies the distance between said idlers andlast-named pulley and regulates the tension of the belt, substantiallyas herein described.

2. The idle pulleys located between the driving and driven pulleys, anda belt engaging said pulleys, in combination with a shaft having aneccentric portion at each end, on which the idlers are mounted, and nutsor headed screws whereby said shaft may be rotated to regulate thetension of said belt, substantially as herein described.

SALMON XV. PUTNAM. lVit-nesses:

CHARLES A. BENNETT, XVILLIAM O. BUXTON.

